Current generations of wireless networks separate shared and dedicated radio resources for devices that provide the corresponding telecommunication services. A dedicated resource, for instance, is an assigned circuit used primarily to transmit and receive voice signals. While some data may be transmitted over the circuit, such that voice and data are transmitted over the same circuit, the circuit is still assigned to the transmitter/receiver. A cellular telephone in a dedicated resource network, for example, would be assigned a particular circuit and data received from or transmitted to the cellular telephone is transmitted over the same circuit. Consequently, systems that enable transmission to and reception from such dedicated networks are commonly called circuit switched systems.
A system using shared radio resources, by contrast, allows information from multiple users to be received and transmitted over a single circuit. The information could be voice or data. Currently, shared radio resources are deployed by systems supporting packet switched services.
It should be noted that the terms “dedicated” and “shared” refer primarily to the usage of physical radio resources on the cell level in a cellular network. In general, cellular telephones or other Radio Frequency (RF) devices in a cell communicate with a base station. The base station communicates this data to the network, which could comprise an aggregate of cellular base stations connected to a Mobile Switching Center (MSC)/GPRS (General Packet Radio Service) Serving Node (GSN) or a conventional telephone system. If there are several cellular users communicating with a base station, each cellular device may (i) periodically transmit information over a certain frequency range (e.g., time multiplexing), (ii) transmit at the same time as other cellular devices, using the same or overlapping frequency ranges (e.g., code-division multiplexing), or (iii) transmit in a particular frequency range (e.g., frequency multiplexing). However, dedicated and shared resources are radio resources that the mobile user needs to access the base station, which then communicates the information received from the cellular users to another user connected to a remote base station via a radio interface or to a fixed line communication device.
Currently, each type of system has its own protocols and is separated through hardware and software. Data meant for one system does not and generally cannot travel through physical radio channels designated for the other system. For instance, data meant for a circuit switched system cannot be delivered via radio resources designated for a packet switched system. There is a movement toward combining circuit switched and packet switched systems in the radio access network. However, current circuit and packet switched systems have been developed at significant cost. Any combined system or protocol for such a combined system should support previous generation systems and protocols.
A need therefore exists for techniques that allow both packet and circuit switching techniques in the same system yet allow previous generation wireless networks to operate correctly.